[pure-silver] Re: [lens] Re: Film vs Digital- was: Amusing Kodak commercial
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Mon, 1 Jan 2007 15:04:14 -0800
----- Original Message -----
From: "tOM Trottier" <tOM@xxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Monday, January 01, 2007 9:49 AM
Subject: [pure-silver] Re: [lens] Re: Film vs Digital- was:
Amusing Kodak commercial
Also
http://www.wilhelm-research.com/hp/HP_International_B9180_Press_Release.pdf
Henry Wilhelm, Wilhelm Imaging Research Inc., (WIR)
said, "With WIR Display Permanence
Ratings of more than 200 years, prints made with the HP
Photosmart Pro B9180 A3+ Photo
Printer, Vivera pigment inks, and select HP glossy photo
papers and matte fine art papers set
a new benchmark for overall colour print permanence.
When displayed framed under glass,
prints made with the new printer, inks, and papers are
among the longest-lasting prints in the
entire 130-year history of colour photography.
"To put this achievement in perspective, displayed
prints made with the HP B9180 and Vivera
pigment inks are five times more stable than the best of
all current traditional dye-based silver
halide colour prints, Fujicolor Crystal Archive prints
(WIR rated at 40 years) -- and more than
ten times longer lasting than Kodak Edge Generations and
Royal Generations prints (WIR
rated at 19 years)."
Pigment prints will last longer than the original colour
films.
Kodak says (
http://www.kodak.com/US/en/motion/support/technical/storage_cond.jhtml )
:
Actually, only safety film (triacetate or polyester
base), which carries silver images, can be
used for extended life expectancy records-500 years for
polyester base and 100 years for
acetate. In some cases, there may be a combination of
nitrate and acetate base films, with
either silver or dye images, that have great historical
value. You may need to preserve these
different films even though you can't afford the expense
to go through the separation method.
The first thing that must be done is to segregate
acetate and nitrate films for storage, because
the two film bases do not mix, and nitrate is not
suitable for any permanent storage record.
Acetate base films can be chemically attacked by the
gases given off by the decomposing,
unstable nitrate-base films. There is no need to
segregate black and-white and color films that
have the same type of base.
This assumes cold dry storage. Pigment prints would last
even longer in these conditions.
The reason "pigment" ink jet inks last is that they are
stable chemicals. Dyes are very unstable,
and silver is subject to oxidation. The substrate also
matters - the paper (or film) has to be very
stable and neutral.
Of course, bits can be propagated forever, but the medium &
technology change every decade or
two.
Happy New Year, tOM
On Monday, January 01, 2007 at 17:47,
Speedy . <pure-silver@xxxxxxxxxxxxx> wrot
Well, pigment ink jet prints are already far more
permanent than our
chemical colour photos, and perhaps even more long-lived
than our
silver prints and negatives. Besides, it's such a hassle
doing
separations....
Happy New Year, tOM
---------------------------------------
My resolution was to stay away from this debate in '07 and
forward,
and that is still my intention.
BUT, couriosity has gotten the best of me. Where, pray
tell, did
this information come from and exactly how reliable is the
source?
Wilhelm seems to be a reliable source. I believe he
originally worked for the Image Permanence Institute of RIT
but had some falling out with them.
It is no news that pigment prints are long lived. The
process known as Carbon or Carbro printing has been in use
for a century. In the 1930's and 1940's three color Carbon
or Carbro was used for making color prints for
photomechanical reproduction, many of these prints still
exist. They were very difficult to make so the process was
not much used beyond the advertising industry. The
introduction of Kodachrome in sheet film sizes and the
improved Kodak Dye Transfer printing method eventually
killed off three color Carbro in the 1950's. Some modern
versions of the process have been introduced but I don't
know if the materials are currently available. Carbon prints
are made from thin gelatin sheets impregnated with pigment
by means of a differential hardening process using Potassium
dichromate. The prints can be exposed via very strong light
(sunlight or a plate burner) or by being in intimate contact
with an ordinary Silver Bromide print for a time. The second
method is known as Carbro. Because of the many variables in
the process it is very difficult to make consistent color
prints. The labs which at one time produced them generally
did nothing else.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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